The present invention is directed, in general, to refrigeration processing systems and, more specifically, to a refrigerant recovery system having an integrated two-phase distillation and filtration path.
Refrigerant recovery systems are used to prevent the loss of refrigerants in refrigerant systems when the refrigerant has to be removed in order to effect repairs or purify the refrigerant upon contamination. Due to the increase in the cost of refrigerants, as well as the growing concern on the adverse effects that refrigerants discharged into the atmosphere have on the environment, refrigerant recovery systems have been used to remove and store the refrigerants of refrigerant systems under repair. Most refrigerant recovery systems also include some scheme for removing contaminates from the recovered refrigerant before transferring the processed refrigerant into storage or back to the repaired refrigerant system.
Conventional refrigerant recovery systems are often incapable of processing multi-phase refrigerant. Specifically, typical refrigerant recovery systems may be capable of either processing predominantly liquid refrigerant or predominantly vaporous refrigerant, but not multi-phase refrigerant having significant proportions of both liquid and vaporous refrigerant. Accordingly, conventional refrigerant recovery systems typically employ individual processing paths for each refrigerant phase. Most often, refrigerant recovery systems employ a phase separation path, which then splits into two paths: a processing path for purifying predominantly liquid refrigerant, and a another processing path for purifying predominantly vaporous liquid refrigerant. Many refrigerant recovery systems further include an additional processing path for removing solid contaminants from the contaminated refrigerant. However, such refrigerant processing in multiple, single-phase processing paths is time-consuming and complex. It requires additional process control observation and operation, because multiple paths may be processing refrigerant concurrently. Such observation and operation is exceedingly complex, increases the total recovery and recycling time, and can decrease the purity of the recycled refrigerant if numerous process controls are not managed with the utmost scrutiny.
In addition, conventional refrigerant recovery systems typically employ two storage tanks having at least one processing path coupled therebetween. The contaminated or processed refrigerant is cycle back and forth between the two storage tanks, each time undergoing processing to further remove contaminants, such as water, grease, oil and rust. However, while contaminants may be removed from the refrigerant as it flows through the processing path between the storage tanks in one direction, the refrigerant is susceptible to re-contamination as it travels back through the processing path in the opposite direction. Obviously, this also decreases the resulting purity of the recycled refrigerant, and can also decrease the operational life of the refrigerant processing components, such as compressors and purifiers, because the contaminants contribute to the corrosion of the component mechanisms and filters. Additionally, this bi-directional processing path further increases the time required to reach a desired refrigerant purity level, if such a level is even obtainable, because the processed refrigerant is susceptible to re-contamination as it flows back through the processing path.
Accordingly, what is needed in the art is a refrigerant recovery system that avoids the disadvantages associated with multiple-path refrigerant processing, including excessive time consumption, operational complexity and compromised refrigerant purity levels.
To address the above-discussed deficiencies of the prior art, the present invention provides a refrigerant recovery system having an accumulator couplable to a system under repair to receive contaminated refrigerant therefrom, a storage tank adapted to receive and store processed refrigerant, and an integrated two-phase distillation and filtration path interposing the accumulator and the storage tank. In one embodiment, the integrated two-phase distillation and filtration path includes a vapor filter, a compressor, a radiator and a liquid filter.
The present invention therefore introduces the concept of performing distillation and filtration of refrigerant in the same fluid path. As discussed above, refrigerant recovery systems conventionally require separate paths for distillation of liquid refrigerant and filtration of vaporous or gaseous refrigerant. Accordingly, refrigerant processing conventionally required phase separation followed by processing of single phase refrigerant in multiple fluid paths. The present invention, however, allows two-phase refrigerant to be processed in an integrated distillation and filtration path, thereby eliminating the conventional steps of phase separation and single phase processing.
In one embodiment of the invention, the refrigerant recovery system includes a return path adapted to selectively deliver processed refrigerant from the storage tank to the accumulator. The processed refrigerant may, thus, undergo multiple iterations of integrated distillation and filtration, which may repeat until a desired level of refrigerant purity is obtained. For instance, in one embodiment, the return path may deliver processed refrigerant from the storage tank to the accumulator while an electronic moisture sensor detects moisture in the processed refrigerant above a predetermined amount. Once the moisture in the refrigerant drops below the predetermined amount, the return path may be deselected or closed and the processed refrigerant may be stored for subsequent return to the system under repair or other purposes.
In one embodiment, the integrated two-phase distillation and filtration path may include valves actuated by a programmable logic control system and interposing ones of the vapor filter, compressor, radiator and liquid filter. In one embodiment, the integrated two-phase distillation and filtration path may have an oil separator interposing the compressor and the storage tank.
In one embodiment, the refrigerant recovery system may further include a purge path that transfers refrigerant from the radiator to the compressor. The purge path may have a purge tank, a heater and a vent. The purge path may contribute to the removal of noncondensable contaminants from the refrigerant.
In one embodiment, the integrated two-phase distillation and filtration path may have a header coupled between the radiator, the liquid filter, an electronic moisture sensor and a purge path. The header may increase the flow efficiency between these processing components, thereby decreasing the required processing time required to reach an acceptable level of refrigerant purity.
In one embodiment, the refrigerant recovery system may include a hand-carryable chassis coupled to and supporting the accumulator, storage tank and integrated two-phase distillation and filtration path. For instance, the chassis may fit into a carrying case movable by one or two workers without the assistance of heavy machinery, or the chassis may be adapted to be worn as a backpack by an individual worker.
In one embodiment, the accumulator may receive the contaminated refrigerant at pressures between about 5 psi and about 300 psi. However, one of ordinary skill in the pertinent art understands that receipt or processing of refrigerant at other pressures is within the scope of the present invention.
In one embodiment, the contaminated refrigerant may be three-phase refrigerant (solid, liquid and gas). However, one of ordinary skill in the pertinent art understands that the present invention may be employed to recover myriad refrigerant types under various conditions.
The foregoing has outlined preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention.